ABSTRACT
Nucleotides are extremely important, they are not only the basic unit of deoxyribonucleic arid and ribonucleic add, but also the basis of high-energy compounds. As for purine synthesis, pyrimidine synthesis occurs in the cytoplasm of cells, and in man, the enzyme activities are part of a multifunctional protein. In multifunctional proteins, the product from one reaction is not actually released into the cytoplasm but remains attached to the enzyme complex. This prevents wastage of products due to degradation and diffusion. The enzyme used for urea synthesis is located in mitochondria, where for pyrimidine synthesis, it is in the cytoplasm. Pyrimidines from nucleic acids are acted upon by nucleotidases and pyrimidine nucleoside Phosphorylase to yield the free bases. To remove excess pyrimidine bases, the ring is simply cleaved to form soluble products, β-amino acids plus ammonia and carbon dioxide.
